SummaryMost hereditary diseases in humans are genetically complex, resulting from combinations of mutations in multiple genes. However synthetic interactions between genes are very difficult to identify in population studies because of a lack of statistical power and we fundamentally do not understand how mutations interact to produce phenotypes. C. elegans is a unique animal in which genetic interactions can be rapidly identified in vivo using RNA interference, and we recently used this system to construct the first genetic interaction network for any animal, focused on signal transduction genes. The first objective of this proposal is to extend this work and map a comprehensive genetic interaction network for this model metazoan. This project will provide the first insights into the global properties of animal genetic interaction networks, and a comprehensive view of the functional relationships between genes in an animal. The second objective of the proposal is to use C. elegans to develop and validate experimentally integrated gene networks that connect genes to phenotypes and predict genetic interactions on a genome-wide scale. The methods that we develop and validate in C. elegans will then be applied to predict phenotypes and interactions for human genes. The final objective is to dissect the molecular mechanisms underlying genetic interactions, and to understand how these interactions evolve. The combined aim of these three objectives is to generate a framework for understanding and predicting how mutations interact to produce phenotypes, including in human disease.

Most hereditary diseases in humans are genetically complex, resulting from combinations of mutations in multiple genes. However synthetic interactions between genes are very difficult to identify in population studies because of a lack of statistical power and we fundamentally do not understand how mutations interact to produce phenotypes. C. elegans is a unique animal in which genetic interactions can be rapidly identified in vivo using RNA interference, and we recently used this system to construct the first genetic interaction network for any animal, focused on signal transduction genes. The first objective of this proposal is to extend this work and map a comprehensive genetic interaction network for this model metazoan. This project will provide the first insights into the global properties of animal genetic interaction networks, and a comprehensive view of the functional relationships between genes in an animal. The second objective of the proposal is to use C. elegans to develop and validate experimentally integrated gene networks that connect genes to phenotypes and predict genetic interactions on a genome-wide scale. The methods that we develop and validate in C. elegans will then be applied to predict phenotypes and interactions for human genes. The final objective is to dissect the molecular mechanisms underlying genetic interactions, and to understand how these interactions evolve. The combined aim of these three objectives is to generate a framework for understanding and predicting how mutations interact to produce phenotypes, including in human disease.

Max ERC Funding

1 100 000 €

Duration

Start date: 2008-09-01, End date: 2014-04-30

Project acronym4C

Project4C technology: uncovering the multi-dimensional structure of the genome

SummaryThe architecture of DNA in the cell nucleus is an emerging epigenetic key contributor to genome function. We recently developed 4C technology, a high-throughput technique that combines state-of-the-art 3C technology with tailored micro-arrays to uniquely allow for an unbiased genome-wide search for DNA loci that interact in the nuclear space. Based on 4C technology, we were the first to provide a comprehensive overview of long-range DNA contacts of selected loci. The data showed that active and inactive chromatin domains contact many distinct regions within and between chromosomes and genes switch long-range DNA contacts in relation to their expression status. 4C technology not only allows investigating the three-dimensional structure of DNA in the nucleus, it also accurately reconstructs at least 10 megabases of the one-dimensional chromosome sequence map around the target sequence. Changes in this physical map as a result of genomic rearrangements are therefore identified by 4C technology. We recently demonstrated that 4C detects deletions, balanced inversions and translocations in patient samples at a resolution (~7kb) that allowed immediate sequencing of the breakpoints. Excitingly, 4C technology therefore offers the first high-resolution genomic approach that can identify both balanced and unbalanced genomic rearrangements. 4C is expected to become an important tool in clinical diagnosis and prognosis. Key objectives of this proposal are: 1. Explore the functional significance of DNA folding in the nucleus by systematically applying 4C technology to differentially expressed gene loci. 2. Adapt 4C technology such that it allows for massive parallel analysis of DNA interactions between regulatory elements and gene promoters. This method would greatly facilitate the identification of functionally relevant DNA elements in the genome. 3. Develop 4C technology into a clinical diagnostic tool for the accurate detection of balanced and unbalanced rearrangements.

The architecture of DNA in the cell nucleus is an emerging epigenetic key contributor to genome function. We recently developed 4C technology, a high-throughput technique that combines state-of-the-art 3C technology with tailored micro-arrays to uniquely allow for an unbiased genome-wide search for DNA loci that interact in the nuclear space. Based on 4C technology, we were the first to provide a comprehensive overview of long-range DNA contacts of selected loci. The data showed that active and inactive chromatin domains contact many distinct regions within and between chromosomes and genes switch long-range DNA contacts in relation to their expression status. 4C technology not only allows investigating the three-dimensional structure of DNA in the nucleus, it also accurately reconstructs at least 10 megabases of the one-dimensional chromosome sequence map around the target sequence. Changes in this physical map as a result of genomic rearrangements are therefore identified by 4C technology. We recently demonstrated that 4C detects deletions, balanced inversions and translocations in patient samples at a resolution (~7kb) that allowed immediate sequencing of the breakpoints. Excitingly, 4C technology therefore offers the first high-resolution genomic approach that can identify both balanced and unbalanced genomic rearrangements. 4C is expected to become an important tool in clinical diagnosis and prognosis. Key objectives of this proposal are: 1. Explore the functional significance of DNA folding in the nucleus by systematically applying 4C technology to differentially expressed gene loci. 2. Adapt 4C technology such that it allows for massive parallel analysis of DNA interactions between regulatory elements and gene promoters. This method would greatly facilitate the identification of functionally relevant DNA elements in the genome. 3. Develop 4C technology into a clinical diagnostic tool for the accurate detection of balanced and unbalanced rearrangements.

SummaryThis project investigates the two-way relationship between spatio-temporal genome organization and coordinated gene regulation, through an approach at the interface between physics, computer science and biology.
In the nucleus, preferred positions are observed from chromosomes to single genes, in relation to normal and pathological cellular states. Evidence indicates a complex spatio-temporal coupling between co-regulated genes: e.g. certain genes cluster spatially when responding to similar factors and transcriptional noise patterns suggest domain-wide mechanisms. Yet, no individual experiment allows probing transcriptional coordination in 4 dimensions (FISH, live locus tracking, Hi-C...). Interpreting such data also critically requires theory (stochastic processes, statistical physics…). A lack of appropriate experimental/analytical approaches is impairing our understanding of the 4D genome.
Our proposal combines cutting-edge single-molecule imaging, signal-theory data analysis and physical modeling to study how genes coordinate in space and time in a single nucleus. Our objectives are to understand (a) competition/recycling of shared resources between genes within subnuclear compartments, (b) how enhancers communicate with genes domain-wide, and (c) the role of local conformational dynamics and supercoiling in gene co-regulation. Our organizing hypothesis is that, by acting on their microenvironment, genes shape their co-expression with other genes.
Building upon my expertise, we will use dual-color MS2/PP7 RNA labeling to visualize for the first time transcription and motion of pairs of hormone-responsive genes in real time. With our innovative signal analysis tools, we will extract spatio-temporal signatures of underlying processes, which we will investigate with stochastic modeling and validate through experimental perturbations. We expect to uncover how the functional organization of the linear genome relates to its physical properties and dynamics in 4D.

This project investigates the two-way relationship between spatio-temporal genome organization and coordinated gene regulation, through an approach at the interface between physics, computer science and biology.
In the nucleus, preferred positions are observed from chromosomes to single genes, in relation to normal and pathological cellular states. Evidence indicates a complex spatio-temporal coupling between co-regulated genes: e.g. certain genes cluster spatially when responding to similar factors and transcriptional noise patterns suggest domain-wide mechanisms. Yet, no individual experiment allows probing transcriptional coordination in 4 dimensions (FISH, live locus tracking, Hi-C...). Interpreting such data also critically requires theory (stochastic processes, statistical physics…). A lack of appropriate experimental/analytical approaches is impairing our understanding of the 4D genome.
Our proposal combines cutting-edge single-molecule imaging, signal-theory data analysis and physical modeling to study how genes coordinate in space and time in a single nucleus. Our objectives are to understand (a) competition/recycling of shared resources between genes within subnuclear compartments, (b) how enhancers communicate with genes domain-wide, and (c) the role of local conformational dynamics and supercoiling in gene co-regulation. Our organizing hypothesis is that, by acting on their microenvironment, genes shape their co-expression with other genes.
Building upon my expertise, we will use dual-color MS2/PP7 RNA labeling to visualize for the first time transcription and motion of pairs of hormone-responsive genes in real time. With our innovative signal analysis tools, we will extract spatio-temporal signatures of underlying processes, which we will investigate with stochastic modeling and validate through experimental perturbations. We expect to uncover how the functional organization of the linear genome relates to its physical properties and dynamics in 4D.

Max ERC Funding

1 499 750 €

Duration

Start date: 2018-04-01, End date: 2023-03-31

Project acronymACTIVATION OF XCI

ProjectMolecular mechanisms controlling X chromosome inactivation

Researcher (PI)Joost Henk Gribnau

Host Institution (HI)ERASMUS UNIVERSITAIR MEDISCH CENTRUM ROTTERDAM

Call DetailsStarting Grant (StG), LS2, ERC-2010-StG_20091118

SummaryIn mammals, gene dosage of X-chromosomal genes is equalized between sexes by random inactivation of either one of the two X chromosomes in female cells. In the initial phase of X chromosome inactivation (XCI), a counting and initiation process determines the number of X chromosomes per nucleus, and elects the future inactive X chromosome (Xi). Xist is an X-encoded gene that plays a crucial role in the XCI process. At the start of XCI Xist expression is up-regulated and Xist RNA accumulates on the future Xi thereby initiating silencing in cis. Recent work performed in my laboratory indicates that the counting and initiation process is directed by a stochastic mechanism, in which each X chromosome has an independent probability to be inactivated. We also found that this probability is determined by the X:ploïdy ratio. These results indicated the presence of at least one X-linked activator of XCI. With a BAC screen we recently identified X-encoded RNF12 to be a dose-dependent activator of XCI. Expression of RNF12 correlates with Xist expression, and a heterozygous deletion of Rnf12 results in a marked loss of XCI in female cells. The presence of a small proportion of cells that still initiate XCI, in Rnf12+/- cells, also indicated that more XCI-activators are involved in XCI. Here, we propose to investigate the molecular mechanism by which RNF12 activates XCI in mouse and human, and to search for additional XCI-activators. We will also attempt to establish the role of different inhibitors of XCI, including CTCF and the pluripotency factors OCT4, SOX2 and NANOG. We anticipate that these studies will significantly advance our understanding of XCI mechanisms, which is highly relevant for a better insight in the manifestation of X-linked diseases that are affected by XCI.

In mammals, gene dosage of X-chromosomal genes is equalized between sexes by random inactivation of either one of the two X chromosomes in female cells. In the initial phase of X chromosome inactivation (XCI), a counting and initiation process determines the number of X chromosomes per nucleus, and elects the future inactive X chromosome (Xi). Xist is an X-encoded gene that plays a crucial role in the XCI process. At the start of XCI Xist expression is up-regulated and Xist RNA accumulates on the future Xi thereby initiating silencing in cis. Recent work performed in my laboratory indicates that the counting and initiation process is directed by a stochastic mechanism, in which each X chromosome has an independent probability to be inactivated. We also found that this probability is determined by the X:ploïdy ratio. These results indicated the presence of at least one X-linked activator of XCI. With a BAC screen we recently identified X-encoded RNF12 to be a dose-dependent activator of XCI. Expression of RNF12 correlates with Xist expression, and a heterozygous deletion of Rnf12 results in a marked loss of XCI in female cells. The presence of a small proportion of cells that still initiate XCI, in Rnf12+/- cells, also indicated that more XCI-activators are involved in XCI. Here, we propose to investigate the molecular mechanism by which RNF12 activates XCI in mouse and human, and to search for additional XCI-activators. We will also attempt to establish the role of different inhibitors of XCI, including CTCF and the pluripotency factors OCT4, SOX2 and NANOG. We anticipate that these studies will significantly advance our understanding of XCI mechanisms, which is highly relevant for a better insight in the manifestation of X-linked diseases that are affected by XCI.

Host Institution (HI)UNIVERSITY COLLEGE DUBLIN, NATIONAL UNIVERSITY OF IRELAND, DUBLIN

Call DetailsStarting Grant (StG), LS2, ERC-2012-StG_20111109

Summary"Ageing is the gradual and irreversible breakdown of living systems associated with the advancement of time, which leads to an increase in vulnerability and eventual mortality. Despite recent advances in ageing research, the intrinsic complexity of the ageing process has prevented a full understanding of this process, therefore, ageing remains a grand challenge in contemporary biology. In AGELESS, we will tackle this challenge by uncovering the molecular mechanisms of halted ageing in a unique model system, the bats. Bats are the longest-lived mammals relative to their body size, and defy the ‘rate-of-living’ theories as they use twice as much the energy as other species of considerable size, but live far longer. This suggests that bats have some underlying mechanisms that may explain their exceptional longevity. In AGELESS, we will identify the molecular mechanisms that enable mammals to achieve extraordinary longevity, using state-of-the-art comparative genomic methodologies focused on bats. We will identify, using population transcriptomics and telomere/mtDNA genomics, the molecular changes that occur in an ageing wild population of bats to uncover how bats ‘age’ so slowly compared with other mammals. In silico whole genome analyses, field based ageing transcriptomic data, mtDNA and telomeric studies will be integrated and analysed using a networks approach, to ascertain how these systems interact to halt ageing. For the first time, we will be able to utilize the diversity seen within nature to identify key molecular targets and regions that regulate and control ageing in mammals. AGELESS will provide a deeper understanding of the causal mechanisms of ageing, potentially uncovering the crucial molecular pathways that can be modified to halt, alleviate and perhaps even reverse this process in man."

"Ageing is the gradual and irreversible breakdown of living systems associated with the advancement of time, which leads to an increase in vulnerability and eventual mortality. Despite recent advances in ageing research, the intrinsic complexity of the ageing process has prevented a full understanding of this process, therefore, ageing remains a grand challenge in contemporary biology. In AGELESS, we will tackle this challenge by uncovering the molecular mechanisms of halted ageing in a unique model system, the bats. Bats are the longest-lived mammals relative to their body size, and defy the ‘rate-of-living’ theories as they use twice as much the energy as other species of considerable size, but live far longer. This suggests that bats have some underlying mechanisms that may explain their exceptional longevity. In AGELESS, we will identify the molecular mechanisms that enable mammals to achieve extraordinary longevity, using state-of-the-art comparative genomic methodologies focused on bats. We will identify, using population transcriptomics and telomere/mtDNA genomics, the molecular changes that occur in an ageing wild population of bats to uncover how bats ‘age’ so slowly compared with other mammals. In silico whole genome analyses, field based ageing transcriptomic data, mtDNA and telomeric studies will be integrated and analysed using a networks approach, to ascertain how these systems interact to halt ageing. For the first time, we will be able to utilize the diversity seen within nature to identify key molecular targets and regions that regulate and control ageing in mammals. AGELESS will provide a deeper understanding of the causal mechanisms of ageing, potentially uncovering the crucial molecular pathways that can be modified to halt, alleviate and perhaps even reverse this process in man."

Max ERC Funding

1 499 768 €

Duration

Start date: 2013-01-01, End date: 2017-12-31

Project acronymANOREP

ProjectTargeting the reproductive biology of the malaria mosquito Anopheles gambiae: from laboratory studies to field applications

Researcher (PI)Flaminia Catteruccia

Host Institution (HI)UNIVERSITA DEGLI STUDI DI PERUGIA

Call DetailsStarting Grant (StG), LS2, ERC-2010-StG_20091118

SummaryAnopheles gambiae mosquitoes are the major vectors of malaria, a disease with devastating consequences for
human health. Novel methods for controlling the natural vector populations are urgently needed, given the
evolution of insecticide resistance in mosquitoes and the lack of novel insecticidals. Understanding the
processes at the bases of mosquito biology may help to roll back malaria. In this proposal, we will target
mosquito reproduction, a major determinant of the An. gambiae vectorial capacity. This will be achieved at
two levels: (i) fundamental research, to provide a deeper knowledge of the processes regulating reproduction
in this species, and (ii) applied research, to identify novel targets and to develop innovative approaches for
the control of natural populations. We will focus our analysis on three major players of mosquito
reproduction: male accessory glands (MAGs), sperm, and spermatheca, in both laboratory and field settings.
We will then translate this information into the identification of inhibitors of mosquito fertility. The
experimental activities will be divided across three objectives. In Objective 1, we will unravel the role of the
MAGs in shaping mosquito fertility and behaviour, by performing a combination of transcriptional and
functional studies that will reveal the multifaceted activities of these tissues. In Objective 2 we will instead
focus on the identification of the male and female factors responsible for sperm viability and function.
Results obtained in both objectives will be validated in field mosquitoes. In Objective 3, we will perform
screens aimed at the identification of inhibitors of mosquito reproductive success. This study will reveal as
yet unknown molecular mechanisms underlying reproductive success in mosquitoes, considerably increasing
our knowledge beyond the state-of-the-art and critically contributing with innovative tools and ideas to the
fight against malaria.

Anopheles gambiae mosquitoes are the major vectors of malaria, a disease with devastating consequences for
human health. Novel methods for controlling the natural vector populations are urgently needed, given the
evolution of insecticide resistance in mosquitoes and the lack of novel insecticidals. Understanding the
processes at the bases of mosquito biology may help to roll back malaria. In this proposal, we will target
mosquito reproduction, a major determinant of the An. gambiae vectorial capacity. This will be achieved at
two levels: (i) fundamental research, to provide a deeper knowledge of the processes regulating reproduction
in this species, and (ii) applied research, to identify novel targets and to develop innovative approaches for
the control of natural populations. We will focus our analysis on three major players of mosquito
reproduction: male accessory glands (MAGs), sperm, and spermatheca, in both laboratory and field settings.
We will then translate this information into the identification of inhibitors of mosquito fertility. The
experimental activities will be divided across three objectives. In Objective 1, we will unravel the role of the
MAGs in shaping mosquito fertility and behaviour, by performing a combination of transcriptional and
functional studies that will reveal the multifaceted activities of these tissues. In Objective 2 we will instead
focus on the identification of the male and female factors responsible for sperm viability and function.
Results obtained in both objectives will be validated in field mosquitoes. In Objective 3, we will perform
screens aimed at the identification of inhibitors of mosquito reproductive success. This study will reveal as
yet unknown molecular mechanisms underlying reproductive success in mosquitoes, considerably increasing
our knowledge beyond the state-of-the-art and critically contributing with innovative tools and ideas to the
fight against malaria.

Max ERC Funding

1 500 000 €

Duration

Start date: 2011-01-01, End date: 2015-12-31

Project acronymBIOSYNCEN

ProjectDissection of centromeric chromatin and components: A biosynthetic approach

Researcher (PI)Patrick Heun

Host Institution (HI)THE UNIVERSITY OF EDINBURGH

Call DetailsStarting Grant (StG), LS2, ERC-2012-StG_20111109

SummaryThe centromere is one of the most important chromosomal elements. It is required for proper chromosome segregation in mitosis and meiosis and readily recognizable as the primary constriction of mitotic chromosomes. Proper centromere function is essential to ensure genome stability; therefore understanding centromere identity is directly relevant to cancer biology and gene therapy. How centromeres are established and maintained is however still an open question in the field. In most organisms this appears to be regulated by an epigenetic mechanism. The key candidate for such an epigenetic mark is CENH3 (CENP-A in mammals, CID in Drosophila), a centromere-specific histone H3 variant that is essential for centromere function and exclusively found in the nucleosomes of centromeric chromatin. Using a biosynthetic approach of force-targeting CENH3 in Drosophila to non-centromeric DNA, we were able to induce centromere function and demonstrate that CENH3 is sufficient to determine centromere identity. Here we propose to move this experimental setup across evolutionary boundaries into human cells to develop improved human artificial chromosomes (HACs). We will make further use of this unique setup to dissect the function of targeted CENH3 both in Drosophila and human cells. Contributing centromeric components and histone modifications of centromeric chromatin will be characterized in detail by mass spectroscopy in Drosophila. Finally we are proposing to develop a technique that allows high-resolution mapping of proteins on repetitive DNA to help further characterizing known and novel centromere components. This will be achieved by combining two independently established techniques: DNA methylation and DNA fiber combing. This ambitious proposal will significantly advance our understanding of how centromeres are determined and help the development of improved HACs for therapeutic applications in the future.

The centromere is one of the most important chromosomal elements. It is required for proper chromosome segregation in mitosis and meiosis and readily recognizable as the primary constriction of mitotic chromosomes. Proper centromere function is essential to ensure genome stability; therefore understanding centromere identity is directly relevant to cancer biology and gene therapy. How centromeres are established and maintained is however still an open question in the field. In most organisms this appears to be regulated by an epigenetic mechanism. The key candidate for such an epigenetic mark is CENH3 (CENP-A in mammals, CID in Drosophila), a centromere-specific histone H3 variant that is essential for centromere function and exclusively found in the nucleosomes of centromeric chromatin. Using a biosynthetic approach of force-targeting CENH3 in Drosophila to non-centromeric DNA, we were able to induce centromere function and demonstrate that CENH3 is sufficient to determine centromere identity. Here we propose to move this experimental setup across evolutionary boundaries into human cells to develop improved human artificial chromosomes (HACs). We will make further use of this unique setup to dissect the function of targeted CENH3 both in Drosophila and human cells. Contributing centromeric components and histone modifications of centromeric chromatin will be characterized in detail by mass spectroscopy in Drosophila. Finally we are proposing to develop a technique that allows high-resolution mapping of proteins on repetitive DNA to help further characterizing known and novel centromere components. This will be achieved by combining two independently established techniques: DNA methylation and DNA fiber combing. This ambitious proposal will significantly advance our understanding of how centromeres are determined and help the development of improved HACs for therapeutic applications in the future.

Max ERC Funding

1 755 960 €

Duration

Start date: 2013-02-01, End date: 2019-01-31

Project acronymBRAINCELL

ProjectCharting the landscape of brain development by large-scale single-cell transcriptomics and phylogenetic lineage reconstruction

Researcher (PI)Sten Linnarsson

Host Institution (HI)KAROLINSKA INSTITUTET

Call DetailsStarting Grant (StG), LS2, ERC-2010-StG_20091118

SummaryEmbryogenesis is the temporal unfolding of cellular processes: proliferation, migration, differentiation, morphogenesis, apoptosis and functional specialization. These processes are well understood in specific tissues, and for specific cell types. Nevertheless, our systematic knowledge of the types of cells present in the developing and adult animal, and about their functional and lineage relationships, is limited. For example, there is no consensus on the number of cell types, and many important stem cells and progenitors remain to be discovered. Similarly, the lineage relationships between specific cell types are often poorly characterized. This is particularly true for the mammalian nervous system. We have developed (1) a reliable high-throghput method for sequencing all transcripts in 96 single cells at a time; and (2) a system for high-throughput phylogenetic lineage reconstruction. We now propose to characterize embryogenesis using a shotgun approach borrowed from genomics. Tissues will be dissected from multiple stages and dissociated to single cells. A total of 10,000 cells will be analyzed by RNA sequencing, revealing their functional cell type, their lineage relationships, and their current state (e.g. cell cycle phase). The novel approach proposed here will bring the powerful strategies pioneered in genomics into the field of developmental biology, including automation, digitization, and the random shotgun method. The data thus obtained will bring clarity to the concept of ‘cell type’; will provide a first catalog of mouse brain cell types with deep functional annotation; will provide markers for every cell type, including stem cells; and will serve as a basis for future comparative work, especially with human embryos.

Embryogenesis is the temporal unfolding of cellular processes: proliferation, migration, differentiation, morphogenesis, apoptosis and functional specialization. These processes are well understood in specific tissues, and for specific cell types. Nevertheless, our systematic knowledge of the types of cells present in the developing and adult animal, and about their functional and lineage relationships, is limited. For example, there is no consensus on the number of cell types, and many important stem cells and progenitors remain to be discovered. Similarly, the lineage relationships between specific cell types are often poorly characterized. This is particularly true for the mammalian nervous system. We have developed (1) a reliable high-throghput method for sequencing all transcripts in 96 single cells at a time; and (2) a system for high-throughput phylogenetic lineage reconstruction. We now propose to characterize embryogenesis using a shotgun approach borrowed from genomics. Tissues will be dissected from multiple stages and dissociated to single cells. A total of 10,000 cells will be analyzed by RNA sequencing, revealing their functional cell type, their lineage relationships, and their current state (e.g. cell cycle phase). The novel approach proposed here will bring the powerful strategies pioneered in genomics into the field of developmental biology, including automation, digitization, and the random shotgun method. The data thus obtained will bring clarity to the concept of ‘cell type’; will provide a first catalog of mouse brain cell types with deep functional annotation; will provide markers for every cell type, including stem cells; and will serve as a basis for future comparative work, especially with human embryos.

Max ERC Funding

1 496 032 €

Duration

Start date: 2010-11-01, End date: 2015-10-31

Project acronymCancerFluxome

ProjectCancer Cellular Metabolism across Space and Time

Researcher (PI)Tomer Shlomi

Host Institution (HI)TECHNION - ISRAEL INSTITUTE OF TECHNOLOGY

Call DetailsStarting Grant (StG), LS2, ERC-2016-STG

SummaryThe metabolism of cancer cells is altered to meet cellular requirements for growth, providing novel means to selectively target tumorigenesis. While extensively studied, our current view of cancer cellular metabolism is fundamentally limited by lack of information on variability in metabolic activity between distinct subcellular compartments and cells.
We propose to develop a spatio-temporal fluxomics approach for quantifying metabolic fluxes in the cytoplasm vs. mitochondria as well as their cell-cycle dynamics, combining mass-spectrometry based isotope tracing with cell synchronization, rapid cellular fractionation, and computational metabolic network modelling.
Spatio-temporal fluxomics will be used to revisit and challenge our current understanding of central metabolism and its induced adaptation to oncogenic events – an important endeavour considering that mitochondrial bioenergetics and biosynthesis are required for tumorigenesis and accumulating evidences for metabolic alterations throughout the cell-cycle.
Our preliminary results show intriguing oscillations between oxidative and reductive TCA cycle flux throughout the cell-cycle. We will explore the extent to which cells adapt their metabolism to fulfil the changing energetic and anabolic demands throughout the cell-cycle, how metabolic oscillations are regulated, and their benefit to cells in terms of thermodynamic efficiency. Spatial flux analysis will be instrumental for investigating glutaminolysis - a ‘hallmark’ metabolic adaptation in cancer involving shuttling of metabolic intermediates and cofactors between mitochondria and cytoplasm.
On a clinical front, our spatio-temporal fluxomics analysis will enable to disentangle oncogene-induced flux alterations, having an important tumorigenic role, from artefacts originating from population averaging. A comprehensive view of how cells adapt their metabolism due to oncogenic mutations will reveal novel targets for anti-cancer drugs.

The metabolism of cancer cells is altered to meet cellular requirements for growth, providing novel means to selectively target tumorigenesis. While extensively studied, our current view of cancer cellular metabolism is fundamentally limited by lack of information on variability in metabolic activity between distinct subcellular compartments and cells.
We propose to develop a spatio-temporal fluxomics approach for quantifying metabolic fluxes in the cytoplasm vs. mitochondria as well as their cell-cycle dynamics, combining mass-spectrometry based isotope tracing with cell synchronization, rapid cellular fractionation, and computational metabolic network modelling.
Spatio-temporal fluxomics will be used to revisit and challenge our current understanding of central metabolism and its induced adaptation to oncogenic events – an important endeavour considering that mitochondrial bioenergetics and biosynthesis are required for tumorigenesis and accumulating evidences for metabolic alterations throughout the cell-cycle.
Our preliminary results show intriguing oscillations between oxidative and reductive TCA cycle flux throughout the cell-cycle. We will explore the extent to which cells adapt their metabolism to fulfil the changing energetic and anabolic demands throughout the cell-cycle, how metabolic oscillations are regulated, and their benefit to cells in terms of thermodynamic efficiency. Spatial flux analysis will be instrumental for investigating glutaminolysis - a ‘hallmark’ metabolic adaptation in cancer involving shuttling of metabolic intermediates and cofactors between mitochondria and cytoplasm.
On a clinical front, our spatio-temporal fluxomics analysis will enable to disentangle oncogene-induced flux alterations, having an important tumorigenic role, from artefacts originating from population averaging. A comprehensive view of how cells adapt their metabolism due to oncogenic mutations will reveal novel targets for anti-cancer drugs.

Max ERC Funding

1 481 250 €

Duration

Start date: 2017-02-01, End date: 2022-01-31

Project acronymCDNF

ProjectCompartmentalization and dynamics of Nuclear functions

Researcher (PI)Angela Taddei

Host Institution (HI)INSTITUT CURIE

Call DetailsStarting Grant (StG), LS2, ERC-2007-StG

SummaryThe eukaryotic genome is packaged into large-scale chromatin structures that occupy distinct domains in the nucleus and this organization is now seen as a key contributor to genome functions. Two key functions of the genome can take advantage of nuclear organization: regulated gene expression and the propagation of a stable genome. To understand these fundamental processes, we have chosen to use yeast as a model system that allows genetics, molecular biology and advanced live microscopy approaches to be combined. Budding yeast have been very powerful to demonstrate that gene position can play an active role in regulating gene expression. Distinct subcompartments dedicated to either gene silencing or activation of specific genes are positioned at the nuclear periphery. To gain insight into the mechanisms underlying this sub-compartmentalization, we will address three complementary issues: - What are the mechanisms involved in the establishment and maintenance of silent nuclear compartments? - How and why are some activated genes recruited to the nuclear periphery? - What are the relationships between repressive and activating nuclear compartments? Concerning the maintenance of genome integrity, recent advances in yeast highlight the importance of nuclear architecture. However, how nuclear organization influences the formation and processing of DNA lesions remain poorly understood. We will focus on two main questions: - How and where in the nucleus are double strand breaks recognized, processed, and repaired? - Where do breaks or gaps resulting from replicative stress at 'fragile sites' arise in the nucleus and how does nuclear organization influence their stability? We hope to gain a better understanding of the mechanisms presiding nuclear organization and its importance for genome functions. These mechanisms are likely to be conserved and will be subsequently tested in higher eukaryotic cells.

The eukaryotic genome is packaged into large-scale chromatin structures that occupy distinct domains in the nucleus and this organization is now seen as a key contributor to genome functions. Two key functions of the genome can take advantage of nuclear organization: regulated gene expression and the propagation of a stable genome. To understand these fundamental processes, we have chosen to use yeast as a model system that allows genetics, molecular biology and advanced live microscopy approaches to be combined. Budding yeast have been very powerful to demonstrate that gene position can play an active role in regulating gene expression. Distinct subcompartments dedicated to either gene silencing or activation of specific genes are positioned at the nuclear periphery. To gain insight into the mechanisms underlying this sub-compartmentalization, we will address three complementary issues: - What are the mechanisms involved in the establishment and maintenance of silent nuclear compartments? - How and why are some activated genes recruited to the nuclear periphery? - What are the relationships between repressive and activating nuclear compartments? Concerning the maintenance of genome integrity, recent advances in yeast highlight the importance of nuclear architecture. However, how nuclear organization influences the formation and processing of DNA lesions remain poorly understood. We will focus on two main questions: - How and where in the nucleus are double strand breaks recognized, processed, and repaired? - Where do breaks or gaps resulting from replicative stress at 'fragile sites' arise in the nucleus and how does nuclear organization influence their stability? We hope to gain a better understanding of the mechanisms presiding nuclear organization and its importance for genome functions. These mechanisms are likely to be conserved and will be subsequently tested in higher eukaryotic cells.